# Favourite numerical sequences

Silverstriker
General 22 Dec '15 15:24
1. 22 Dec '15 15:24

Im trying to make a list of fascinating numerical sequences as part of a display in a classroom. I like sequences such as Fibonacci and Triangular sequences but any different ones that people like on here?
2. rookie54
free tazer tickles..
22 Dec '15 15:47
i've been fascinated by prime numbers since i was a child...
they don't seem to make pretty patterns, no matter how i lined them up, but, that single property of being unique, only divisible by itself and one (1), that i like...
3. 22 Dec '15 17:17
Originally posted by Silverstriker

Im trying to make a list of fascinating numerical sequences as part of a display in a classroom. I like sequences such as Fibonacci and Triangular sequences but any different ones that people like on here?[/b]
4. sonhouse
Fast and Curious
22 Dec '15 19:411 edit
I like this formula: RU/18
5. moonbus
Uber-Nerd
22 Dec '15 22:10
Pythagorean triples less than 100:

(3, 4, 5), (5, 12, 13), (7, 24, 25), (8, 15, 17), (9, 40, 41), (11, 60, 61), (12, 35, 37), (13, 84, 85), (16, 63, 65), (20, 21, 29), (28, 45, 53), (33, 56, 65), (36, 77, 85), (39, 80, 89), (48, 55, 73), (65, 72, 97)
6. wolfgang59
surviving
22 Dec '15 23:13
Originally posted by Silverstriker

Im trying to make a list of fascinating numerical sequences as part of a display in a classroom. I like sequences such as Fibonacci and Triangular sequences but any different ones that people like on here?[/b]
What age range are we talking about?
7. rookie54
free tazer tickles..
22 Dec '15 23:18
Originally posted by moonbus
Pythagorean triples less than 100:

(3, 4, 5), (5, 12, 13), (7, 24, 25), (8, 15, 17), (9, 40, 41), (11, 60, 61), (12, 35, 37), (13, 84, 85), (16, 63, 65), (20, 21, 29), (28, 45, 53), (33, 56, 65), (36, 77, 85), (39, 80, 89), (48, 55, 73), (65, 72, 97)
omg!!!
you made me learn something i NEVER knew before!!!
for the FIRST TIME IN MY LIFE i know

very little... ðŸ˜ž ðŸ˜ž ðŸ˜ž

https://www.mathsisfun.com/numbers/pythagorean-triples.html
8. sonhouse
Fast and Curious
23 Dec '15 10:39
Originally posted by rookie54
omg!!!
you made me learn something i NEVER knew before!!!
for the FIRST TIME IN MY LIFE i know

very little... ðŸ˜ž ðŸ˜ž ðŸ˜ž

https://www.mathsisfun.com/numbers/pythagorean-triples.html
Nice site! Did I detect a tiny but noticeable thread of implied sarcasm here?

One thing I wondered about. If Pathags are infinite but a smaller number of the full set of real numbers, doesn't that make the infinity of real numbers bigger than the infinity of Pathags?
9. moonbus
Uber-Nerd
23 Dec '15 13:25
Originally posted by sonhouse
One thing I wondered about. If Pathags are infinite but a smaller number of the full set of real numbers, doesn't that make the infinity of real numbers bigger than the infinity of Pathags?
You go wonky if you try to think about different infinities as being bigger or smaller than other ones. Think of infinities as having characteristics, not 'sizes'; denumerability is an example of a characteristic.

For example, the set of natural numbers (1,2,3,4) can be put into 1:1 correspondence with the set of even numbers (2,4,6,8), which means they are equivalently denumerable -- this is counterintuitive, because one thinks the set of even numbers must be smaller, since all the odd numbers are missing.
10. 23 Dec '15 14:17
Originally posted by sonhouse
I like this formula: RU/18
Erm... what does it stand for?
11. 23 Dec '15 14:28
Originally posted by sonhouse
Nice site! Did I detect a tiny but noticeable thread of implied sarcasm here?

One thing I wondered about. If Pathags are infinite but a smaller number of the full set of real numbers, doesn't that make the infinity of real numbers bigger than the infinity of Pathags?
If by "Pathags" you mean Pythagorean triple numbers... those aren't real numbers in the first place. They're integers.
OK, all integers are also real numbers... but you know what I mean
So the infinity of real numbers is greater than the infinity of members from Pythagorean triples by definition: c is greater than aleph-zero.
12. sonhouse
Fast and Curious
23 Dec '15 16:47
Originally posted by Shallow Blue
Erm... what does it stand for?
So the guy asks the girl he just encounters: R U over 18?
13. rookie54
free tazer tickles..
23 Dec '15 16:57
Originally posted by sonhouse
Nice site! Did I detect a tiny but noticeable thread of implied sarcasm here?
normally, sarcasm is my goto post...
in this case, i really learned a new thing in my life,
and,
while i cannot yet find a use for it (even in my shop) this is a wonderful bit of knowledge for me...

14. moonbus
Uber-Nerd
26 Dec '15 09:35
Originally posted by sonhouse
So the guy asks the girl he just encounters: R U over 18?
Slightly bumpish, but a famous line of Shakespeare can be rendered in symbolic logic: 2 B V 0 2 B

To be or not (naught) to be.
15. 27 Dec '15 20:40
Originally posted by moonbus
Slightly bumpish, but a famous line of Shakespeare can be rendered in symbolic logic: 2 B V 0 2 B

[hidden]To be or not (naught) to be.[/hidden]
Alternatively, 2b ∨ ¬2b .